PORTLAND — U.S. Rep. Mike Michaud on Friday introduced a bill that would mandate a minimum crew of two for freight trains in the aftermath of a runaway train derailment that killed 47 people in Canada.

Canadian transportation officials already issued a directive banning solo-operator crews for trains hauling dangerous materials following the July 6 derailment in Lac-Megantic, Quebec, 10 miles from the Maine border. A Montreal, Maine & Atlantic Railway executive blamed the train’s operator for failing to set enough hand brakes.

There’s nothing to indicate an extra crew member would have made a difference, but some observers expressed surprise that one person had been in charge of an oil train that was nearly a mile long.

Michaud, whose bill is co-sponsored by fellow Maine Democratic Rep. Chellie Pingree, said having at least two crew members instead of just one would make trains safer.

“After meeting with federal agencies and hearing from Mainers and experienced train operators, it’s clear to me that there is a significant safety advantage in having two or more people operating a freight train,” said Michaud, adding that it’s just “common sense that having another person on that train is going to be better than just one.”

In the United States, most large railroads use crews of two or more for freight trains but some regional rail lines have reduced their crew sizes to the bare minimum to save money. The Federal Railroad Administration declined in 2009 to mandate a two-person crew following a petition by two unions.

Pingree and Michaud have met with the leaders of the Pipeline and Hazardous Materials Safety Administration, the National Transportation Safety Board and the Federal Railroad Administration following their request for a safety review of Maine’s rail infrastructure.

Pingree called the bill a good first step to addressing some of the safety concerns raised by the Lac-Megantic tragedy.

“With freight trains’ potentially hazardous cargo and sheer size, it makes sense on many levels to have at least two people on a crew at all times,” she said. “Having only one person onboard who is responsible for a train’s safe operation simply allows too much room for errors to go uncorrected.”